Propeller.



T. AMNELIUS.

PR OPELLER. APPLICATION FILED SEPT. 3, 1910.

1, 1 23,202. Patented Dec. 29, 1914.

3 SHEETS-SHEET 1.

T. AMNELIUS. PROPELLBR.

APPLICATION FILED SEPT. a, 1910.

1,1 28,202., Patented Dec. 29, 1914.

3 SHEETS-SHEET 2.

wu'neoom j T. AMNELIUS.

PROPELLER.

APPLIOATION'FILED SEPT. s, 1910.

1,123,202, I Patented Dec. 29, 1914.

3 SHEETS-SHEET 8.

UNITED STATES PATENT OFFICE.

THEODORE AMNELIUS, OF SOUTH FRAMINGHAM, MASSACHUSETTS.

PROPELLER.

Specification of Letters Iatent.

Application filed September 3, 1910. Serial No. 580,313.

To all whom it may'concernf Be it known that I, THEODORE AMNELIUs,

I .a citizen of the United States, residing at and when rotating at thesame rate.

' South 'Framingham,

A further object of my invention is to provide a propeller which shallhave but little centrifugal action upon the water adjacent thereto.

Other objects will appear hereinafter.

With these objects in view my invention consists generally in apropeller having a blade so shaped as to transform the centrifugalmovement or action of the water at or near the hub into a rearward andpreferably inward direction as it approaches the periphery or outer endof the blade.

My invention further consists in certain novel details and forms ofconstruction whereby the normal centrifugal force is overcome and causedto condense the medium behind the propeller and rarefy or decrease itsdensity in front of the propeller.

My invention further consists in various details of construction andarrangements of parts all as will be fully described hereinafter andparticularly pointed outin the claims.

My invention will be more readily understood by reference to theaccompanying drawings'forming apart of this specification and in which-Figure I is a rear elevation "of a propeller embodying my invention inits most simple form, Fig. II is a transverse section through one of theblades on the line II--II of Fig. I, Fig. III is an edge view of thepropeller, Fig. IV is a diagram of the forces acting at differentsections of the blade, Fig. V is a modified form ofthe propellerillustrated in Fig. I, each blade being, formed of a plurality of curvedsurfaces or sections, Fig. VI is an end view thereof, Fig. VII

is a rear view of a further modification lines indicated the blade intoa rearward toward the outer end. This will be clear by referring to thelines of force indicated of my invention each blade being formed with asingle curved operative face, Fig. VIII isan edge view of the same, Fig.IX 1s a further modification, the blade being formed of three angular-1ydisposed faces and the center face being concave, Fig.

Patented Dec. 29, 1914..

is an end view of the blade illustrated in Fig. XV, Fig. XI is anelevation of a propeller havlng two blades such as illustrated in Flgs.XI and XII, and equipped with sub-blades of opposite configuration, Fig.

XII is a side elevation thereof; Fig. XIII is an end view of one of theblades and,

sub-blades, Fig. XIV is a further modified form of my inventionillustrating a propeller particularly adapted for aviation each bladebeing composed of a plurality of sectlons each section similar to theblade illustrated in Figs. I and V, and Fig. XV is an end view of theblade illustrated in Fig. XIV.

Referring now to the drawings, particularly to Figs. I to IV inclusive,1 indicates the hub of the propeller and 2 the blades.

Each blade is formed with its front edges 3 and rear edges 4 lying inparallel planes, and preferably in the same plane as the ends of the hub1, and transverse sections of the blade taken successively from the rootof the blade to its outer end are at lncreasing angles to the axis ofrotation. This will be clear by referring to Figs. III and IV, the linesa, Z), 0', d and e in said figures, indicating the similar imaginaryFig. I.

On one of the blades in Fig. I is illustrated a longitudinal sectiontaken centrally through the blade to illustrate clearly the centralthickness of the blade, the edges being sharp, but more particularly toshow the longitudinal curvature of the same. It will be noted that thecurvature longitudinally of the blade increases from the hub toward theperiphery. This curvature, together with the increasing angle of theblade to the axis of rotation, combine to produce a propellercentrifugal action on the medium surrounding the same and which willtransform the centrifugal force at the inner portion of condensing forceby the arrows in the several figures.

by the dotted lines on which has but little' The rapid rotation of thepropeller naturally tends to create centrifugal force on the medium andmove the same outwardly from the hub. The outwardly flowing me diumalong the blade is deflected more and more as it approaches the end ofthe blade due to the increasing curvature of the blade longitudinally,the angle of deflection being the same as the angle of incidence. Seearrows in Fig. I. The longitudinal curvature of the blades also causesthe outer ends to move in advance of the portions toward the center.This outer end, owing to its longitudinal curvature and its angularposition with relation to the axis of rotation, gathers the medium andforces it inwardly to be acted upon by the inner portions of the bladewhere the angle to the axis of rotation constantly decreases, and wherea greater rearward force is thereby exerted on the medium. Thiscondenses the medium to a great degree behind the propeller and createsa rarefied medium in advance of the same. The inner end of the blade,owing to its slight angular position with relation to the axis ofrotation and the outward flow of medium at this portion, creates apartial vacuum behind the same near the hub, therebv drawing in mediumfrom in front to be acted upon by the next blade in succession.

In Figs. V and VI I have illustrated a propeller in which each blade iscomposed of two sections 5 and 6, each'section constructed on the sameprinciple as the single blade illustrated in Figs. I and III, and inFigs. XIV and XV have illustrated a propeller blade formed of three suchsections 7, 8 and 9. In each of those propellers each section acts onthe medium in a manner similar to that described in regard to the blade2.

The propeller illustrated in Fig. XIV is particularly adapted foraviation and for such use I prefer to form the increasing longitudinalcurvature more pronounced.

In Figs. VII and VIII I have illustrated a modified form wherein theincreasing longitudinal curvature and the angular disposition of theparts of the blade are substantially the same as in the preceding forms,but the forward edge of the blade is produced or extended toward thecenter beyond the plane of the forward end of the hub. This gives thepropeller the function of scooping the water from in front and therebyincreasing the condensation of the same behind the blade. In form theforward edge lies in a plane substantially radial to the axis ofrotation or in a plane parallel with such radial plane. l

Figs. IX and. -X illustrate the further modifications of the propellerin which each blade is formed of three sections.

with the central section 15 concavely formed similar to the blade shownin Fig.

VII. It is obvious that a propeller may be constructed each blade formedof several sections and each section conforming to the structure shownin Figs. VII to X inclu- I SlVe.

In Figs. XI, XII and XIII I have illustrated a further modification ofmy invention wherein the propeller is composed of a plurality ofprincipal blades 16 and a like number of sub-blades 17. As illustratedin the figures mentioned the principal blades have the form illustratedin Fig. VII and the sub-blade a form similar to the blades shown in Fig.I except reversed, the operative faces of each blade and its sub-bladebeing of opposite configuration. By the use of the sub-blade a greatercondensation of the medium is had and less agitation of the same.Structurally, each sub-blade is formed separately and provided with abase plate 18 which is bolted or otherwise secured to the hub 1. It isobvious that the propeller blades may partake of any of the formshereinbefore described, but in each incident I prefer that the sub-bladeshall be of similar form.

While the different forms of the invention disclose variances instructural detail, the operative faces of the blades in all of the formsillustrated are straight from the front to the back edge, and it isobvious that such arrangement permits of the rotation of the propellerwith the least amount of friction of back pressure due to the resistanceof the element through which it is rotating.

Having described my invention what I claim as new and desire to secureby Letters Patent is l. A propeller blade having an operative faceformed longitudinally with an increasing curvature from'the center tothe end and successive sections through the operative face beingstraight from front to back edge and lying at increasing angles to theaxis of rotation from the inner to the outer end thereof.

2. In a propeller, a blade formed with an operative face having anincreasing longitudinal curvature from its inner to its outer end,successive sections thereof trans versely of the blade beingstraightfrom front to back edge and lying at increasing angles to theaxis of rotation and the forward edge of the blade at the center beingextended beyond the plane of the ends of said edge, substantially asdescribed. 3. A propeller comprising a'plurality of main blades eachformed with an operative face having an increasing longitudinalcurvature from its inner to its outer 'end with successive sectionsthereof transversely of the blade'l'yingat increasing angles to the axisof rotation,- the said operative face being straight from front to backedge, and

a sub-blade for each of said main blades, each of said sub-blades beingof the same configuration as said main blade but being oppositelydisposed with relation to said main blades to coact therewith,substantially as described.

In testimony whereof I have signed my THEODORE AMNELIUS.

Witnesses:

Moses T. GLODE, JOHN H. Ceocm.

